In this paper we attempt to develop a new system called “C-Navi” for construction site simulation and management system. By integrating AR technology with mobile computing, the new system will extend the abilities of AR systems to be implemented in large outdoor space. The concept of 4D CAD system is utilized by integrating related information and displaying them in the time-based visualization approach. Our system could help with decision making and also act as a tool for improved communications between project partners.